Munster coach Tony McGahan was left to rue a bittersweet 22-16 victory at Thomond Park as Paul O'Connell was red-carded 10 minutes into his Heineken Cup comeback.

The province's inspirational captain received his marching orders after his swinging right arm appeared to make contact with Ospreys No.8 Jonathan Thomas, who ended up in a heap on the floor. Referee Christophe Berdos did not see the incident at first but after consultation with his assistant David Rose, he decided that a red card was justified.

Speaking immediately after the match, a slightly stunned McGahan revealed he had yet to speak to his captain, preferring to let him cool down after what could be a defining moment in Munster's season.

As for his own thoughts on the incident, McGahan said: "I was hoping I was colour blind! But unfortunately my eyesight is good enough because I'm still young.

"We had a brief look at it. We really haven't looked at it in enough depth to give any real comment. What we saw was the same as what everyone else saw, a reaction to (Thomas) holding onto the jersey. I'll have to give it a bit more thought. It doesn't serve any purpose for us to get caught up in that while the game was going on.

"I was shocked really, but we just had to get on and deal with it."

Ospreys forwards coach Jonathan Humphreys also gave his view on the episode, commenting: "First of all, Paul O'Connell is not a dirty player by any stretch of the imagination.

"A very similar thing happened to Gavin Henson for a similar incident and unfortunately he got 10 weeks for that. We have a lot of admiration for Paul as a player. He's a very iconic figure here. So it's very disappointing for him. He could miss a large chunk of the season now."

The Ospreys led thanks to Dan Biggar's second-minute penalty and a long-range intercept try from Tommy Bowe, in the opening minutes of the second half, had them leading by 13-8. In the end, Biggar's third successful penalty garnered them a losing bonus point ahead of the Liberty Stadium leg next weekend.

O'Connell's red card was the only blot on an otherwise satisfactory day for Munster, who overturned that 13-8 deficit with converted tries from David Wallace and Johne Murphy. Doug Howlett scored their first half try.

"It's a tough pool, and to win at home is really important for our outlook on the rest of the games," admitted McGahan. "When you're behind 13-8 with fifty minutes on the clock, you're just looking to get a result, and that was our whole focus of the game.

"We'd have liked to deny the opposition that but they were good enough to get it, so you have to give respect."